Trisomy 9 screened positive for trisomy 18 by maternal serum screening

Case report: A case report and literature review of complete trisomy 9

Complete trisomy 9 is a rare and lethal chromosomal anomaly characterized by multisystem dysmorphism and central nervous system (CNS) malformations. This study presents a case of complete trisomy 9 with an unusual phenotypic association and investigates the genetic pathways involved in this chromosomal abnormality. Trisomy 9 leads to a wide range of organ abnormalities, and this research contributes to a better understanding of the phenotype associated with this rare aneuploidy. The literature on the phenotypes of fetuses with various systems affected by complete trisomy 9 was reviewed and summarized. Correct diagnosis and appropriate counseling based on the characteristics of previous reports of fetuses with trisomy 9 is essential in maternity care and clinical management. To provide guidance and help for clinical diagnosis, this study aimed to explore the clinical and genetic characteristics of trisomy 9 syndrome to improve clinicians' understanding of the disease.

Partial trisomy 9: prenatal diagnosis and recurrence within same family

Trisomy 9 can be suspected and confirmed in the prenatal period since the 11–13.6 weeks of screening. In cases of partial trisomy 9, the diagnosis is important especially to counseling the couple due to the increased likelihood of recurrence in subsequent pregnancies.

Ultrasound diagnosis of central nervous system anomalies (bifid choroid plexus, ventriculomegaly, Dandy-Walker malformation) associated with multicystic dysplastic kidney disease in a trisomy 9 fetus: case report with literature review

Trisomy 9 is a lethal chromosomal abnormality that rarely progresses beyond the second trimester of pregnancy. Multiple central nervous system anomalies, including bifid choroid plexus, ventriculomegaly, and Dandy-Walker malformation, associated with multicystic dysplastic kidney disease in a trisomy 9 fetus are reported. The prenatal ultrasound diagnosis has been aided by novel three-dimensional ultrasound software.